Manufacture of artificial threads



Patented Sept. 24, 1935 ATENT QFFIE MANUFACTURE OF ARTIFICIAL THREADS Thomas F. Banigan, Richmond, Va., assignor to Du Pont Rayon Company, New York, N. Y., a corporation of Delaware a No Drawing. Application February 27, 1931,

Serial No. 518,911

12 Claims. (01. 18--54) This invention relates to the production of artificial thread. More particularly this invention relates to the production of artificial thread from viscose. Still more particularly the invention relates to an improvement in the handling and purifying of regenerated cellulose threads.

In the method of making artificial thread wherein a solution of cellulosic material is regenerated and wound to a considerable thickness on a rigid bobbin and wherein the thread is subsequently purified and dried on the bobbin, the outer windings of thread, which are laid on the compressible underwindings, shrink considerably in the purification and drying whereas the windings close to the rigid core are prevented from shrinking. This causes the finished thread to have uneven denier, varying strength, and dyeing characteristics which are not uniform. Heretofore it has been practically impossible to obtain a thread of uniform characteristics by this method if the thread is purified on the bobbin. In the past it has been found desirable to take the spun thread from the bobbin and gather'it into loose skeins before purification, or to spin onto inserts or non-rigid bobbins. These processes have not been entirely satisfactory, however, because in the skein process the yarn acquires broken filaments, knots, kinks, and cut or broken threads through handling, and in the insert process imperfect equalization and purification result.

It is an object of this invention to improve the manufacture of artificial thread. It is another object of the invention to improve the handling and purification of regenerated cellulose threads which have been spun on bobbins. Other objects of the invention will be in part apparent and in part set forth as the description proceeds.

In the practice of my invention a thread of regenerated cellulose is drawn from the regencrating bath and wound upon a rigid bobbin, where it is Washed free of the regenerating liquid and allowed to dry. Thereafter it is rewound upon a second rigid bobbin with or without twist,- ing of the thread, is purified, and allowed to dry. The thread which is on the outside of the first bobbin shrinks, while that which is next to the core is unable to shrink. After re-winding the condition is reversed, the thread which was next to the core on the first bobbin being on the outside of the re-wind bobbin and capable of shrinking in its turn, While the thread on the outside of the first bobbin is next to the core of the re-wind bobbin and unable to shrink further.

In re-winding it is advantageous to so wind the threads on the bobbin that the cake will be porous and relatively open to purifying liquids.

Twisting the thread during re-winding and before desulfuring and purification materially assists in the formation of a porous cake and also has the very important result, in combination with the subsequent purifying and drying, of giving the twist of the finished thread a permanent set. This is particularly advantageous because much trouble has been heretofore caused by the lack of permanence of the twist in the threads prepared by prior processes.

After the re-winding is complete the cake of dry, preferably twisted, thread can be moistened and dried or can be treated on the bobbin according to any known process. For instance, it can be desulfured, bleached, tinted, sized, and washed. These processes can be carried out by simply immersing the bobbin in suitable solutions with or without agitation to assist the removal of impurities and the penetration of the solution through the windings of the thread. After the purification and such other treatments as are desirable, the thread is allowed to dry.

This invention is applicable to any known method of producing thread in which thread is wound upon a spool or bobbin and allowed to dry and shrink there, and embraces all processes using materials such as viscose or cuprammonium cellulose. The processs is not limited touse with rigid bobbins but, of course, may be used with the non-rigid type of bobbin wherever such use produces beneficial results.

Twisting of the thread need not be resorted to during re-winding nor is it necessary to re-wind 5 openly on the re-wind bobbin, but each of these steps produces an improved result.

The re-wind bobbin with its thread may be washed in any known manner, as for instance, by pressure washing, or vacuum washing, or im- 40 mersion washing, and any purification, dyeing, or bleaching processes may be carried out while the thread is on the bobbin.

An advantage of my invention is that it is possible to spin on to the first bobbin for a much longer time than heretofore. For instance, I spin on to a bobbin for six hours instead of the three hours permissible in previous methods, it being understood that the spinning time is subject to variation according to the denier of the particular thread spun. This isa great advantage in reducing the handling and treating time heretofore necessary in the manufacture of a given quantity of thread.

Another advantage of my process lies in the astonishing uniformity and superiority of the thread produced. The thread is so uniform that the variation in denier is less than the error involved in the customary denier test. Furthermore, the thread is, generally speaking, of higher quality as regards color and softness than threads produced by similar prior processes.

Another advantage of my invention lies in that the permanent set which is given to the twist of the thread prevents kinking, tangling, and breaking, and results in a thread which has far fewer broken filaments, cut threads, knots, and kinks than threads produced by similar prior processes.

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that I do not limit myself to the specific embodiments thereof except as defined in the appended claims.

I claim:

1. The method of preparing an artificial thread which comprises winding a moist contractible thread on a bobbin, drying the thread, re-winding the thread an another bobbin with twisting, moistening, and drying.

2. The method of preparing artificial thread which comprises winding a thread on a bobbin, shrinking the thread, re-winding upon another 'bobbin, and again shrinking the thread.

3. In the manufacture of contractible artificial thread the method which comprises shrinking at one end while substantially preventing shrinkage at the other end and thereafter shrinking at the other end while substantially preventing shrinkage at the first end.

4. The method of preparing artificial thread which comprises winding a thread on a bobbin, washing, drying, re-winding on another bobbin,

"moistening, and drying.

5. The method of preparing artificial thread which comprises spinm'ng a thread of regenerated cellulose onto a bobbin, washing and drying the thread, rewinding the thread on another bobbin with twisting, purifying the thread, and drying.

6. The method of preparing an artificial thread which comprises winding a thread of regenerated cellulose onto a bobbin, shrinking the thread, rewinding upon a second bobbin in open and twisted manner, wetting, and again shrinking the thread.

7. In the treatment of contractible artificial thread the method which comprises spinning contractible thread upon a bobbin, shrinking the thread, thereafter winding upon another bobbin, and again shrinking the thread.

8. In a method of treating spooled artificial filaments, and the like the steps of wet-treating, drying, rewetting and redrying, the filaments and the like being rewound onto another holder between the first and second drying.

9. In a method for producing a yarn with an even contraction and strength, the steps of spooling, wet-treating and drying the yarn, rewinding so that the yarn formerly on the outer side of the holder is on the inside, then rewetting and redrying the yarn.

10. In a process for the production of yarn with even shrinkage, the steps of extruding the yarn, winding it onto spools, wet treating it, rewinding onto other spools so the yarn formerly on the inner side of the spool body is later on the outer side, rewetting and redrying.

11. The method of preparing an artificial thread which comprises winding a thread on a bobbin, rewinding the thread on another bobbin so that the exterior windings on the first bobbin are next to the core on the second bobbin, the thread being shrunk on each bobbin by drying, and in each instance being moistened before shrinking.

12. The method of producing an even shrinkage in a thread of shrinkable material which comprises winding the thread upon a support and causing the outer windings to shrink against the resistance of the inner windings, unwinding the thread and winding it upon a support so that the windings outside during the first shrinking are next to the support during the second, and causing the outer windings on the second support to shrink against the inner windings.

THOMAS F. BANIGAN.

CER'HFECATE 9F CQRREQTIQN,

eeieeehe. 15392. September 24, 1935.

THOMAS F. BANIGAN.

it is hereby certified that error appears in ehe printed specification of the above numbered patent requiring cerrection as fellows: Page 2, first column, line 25, claim i, 502* "he" read mm; and em -the said Letters Patent should be read with this eei'eectieh aherein that the samemay eenferm to the record of the case in the Patent @flice,

Sign-me seeied this 12th day of November, A. H 1.935.

Leslie Frazer (Sea!) Acting Gommissioner 0i Patents. 

